We have published an XPS study comparing two methods for poly-caprolactone surface functionalisation with cell-binding RGD peptides.
Immobilisation of Cell-Binding Peptides on Poly-ε-Caprolactone (PCL) Films: A Comparative XPS Study of Two Chemical Surface Functionalisation Methods
J.S. Stevens, A.C. de Luca, S. Downes, G. Terenghi, S.L.M. Schroeder
Surface and Interface Analysis (2014) early view.